intelligent

(a) having the capacity for thought and reason especially to a high degree
- is there intelligent life in the universe?
- an intelligent question
(s) possessing sound knowledge
- well-informed readers
well-informed,
(s) exercising or showing good judgment
- healthy scepticism
- a healthy fear of rattlesnakes
- the healthy attitude of French laws
- healthy relations between labor and management
- an intelligent solution
- a sound approach to the problem
- sound advice
- no sound explanation for his decision
levelheaded, level-headed, sound, healthy,
(s) endowed with the capacity to reason reasoning, thinking,

well-informed levelheaded level-headed sound healthy reasoning thinking

unintelligent stupid

intelligently intelligentsia